Motor-assisted hand-movable cart

ABSTRACT

A motor-assisted hand-movable cart that can have an identical cart inserted into it in a space-saving manner, whereby the cart is provided with: a drive chassis having two front casters and two back casters; a pushing device; a storage device for goods; a support section below the storage device, on which is disposed at least one running wheel that is located between the two front and the two back casters, and an electromotor drive unit, this drive unit driving the at least one running wheel; and a power source for supplying the electromotor drive unit located in a space not required by a further pushcart to be inserted into the pushcart during the insertion process.

BACKGROUND OF THE INVENTION

The invention relates to a motor-assisted hand-movable pushcart that canbe inserted into an identical pushcart in a space-saving manner, wherebythe pushcart is provided with a drive chassis having four casters and apushing device and a storage device for goods, and whereby below thestorage device is a support section on which is disposed at least onerunning wheel that is located between the two front and the two backcasters.

Pushcarts of this type are described in more detail in U.S. Pat. No.4,826,186 and European Patent No. 0 352 647 B1. The at least one runningwheel has a stabilizing effect on the steering and pushing process inpushcarts of this type. The running wheels are furthermore disposed insuch a way that the pushcarts can be pushed relatively tightly insideeach other. In self-service markets, this makes it possible to save muchstorage space when parking or making available these pushcarts in rows.The advantages just described have caused such pushcarts to be verypopular. However, if these pushcarts are heavily loaded, the same amountof pushing force must be applied as for pushcarts with no running wheelin the center. For this reason, pushcarts were developed that areprovided with four wheels and/or casters and have a controllable,electromotor-driven drive unit intended to propel or move the pushcartby acting via the wheels or an additional drive wheel. One of manypushcarts of this type is described, for example, in U.S. Pat. No.5,746,282. The drive unit hereby acts supporting during the pushing of aheavily loaded pushcart by hand. But the pushcarts mentioned last cannotbe inserted inside each other in a space-saving manner.

The objective of the invention is to further develop a pushcart of thisclass type in such a way that if the known advantages that can beobtained with a centered running wheel and by using a controllable driveunit are utilized, the ability of inserting the pushcarts into another,identical pushcart is not adversely affected.

SUMMARY

This objective is realized in that at the support section a drive unitsupplied by a power source is provided, this drive unit being intendedfor driving the at least one running wheel, and that the power source onthe pushcart is located in at least one of the spaces not required by apushcart to be inserted into it during the insertion process.

The objects can be achieved with a motor-assisted hand-movable cart thatcan have a further identical cart inserted into it in a space savingmanner, whereby the cart is provided with a drive chassis having fourcasters, including two front casters and two back casters; a pushingdevice; a storage device for goods; a support section below the storagedevice, on which is disposed at least one running wheel that is locatedbetween the two front and the two back casters, and an electromotordrive unit, this drive unit being intended for driving the at least onerunning wheel; and a power source located in a space not required byfurther cart to be inserted into the cart during the insertion process.

It is advantageous to arrange the drive unit on the support section thatexists in any case, since the running wheel is located there. If thesupport section is arranged so as to be swivelable about a horizontalaxis, the weight of the drive unit contributes in pushing the runningwheel even more against the ground, in this way increasing the driveforce of the running wheel. It is further useful, to arrange the powersource that is usually made up of batteries in those spaces not requiredby one of the two pushcarts when two pushcarts are inserted inside eachother. Such areas are usually located below the storage device in thefront part of the drive chassis and in the back part below the pushingdevice, whereby they are in the latter case arranged higher than thestorage device, however. In this way, the power source and the driveunit do not adversely affect either the space-saving inserting inside ofeach other of the pushcarts, nor do they claim space or room on or atthe storage device.

The invention is explained in more detail in reference to exemplaryembodiments, whereby the exemplary embodiments preferably take theirorientation from the construction of those pushcarts described in theinitially mentioned European patents.

DRAWINGS

FIG. 1 shows a pushcart with swivelable support section;

FIG. 2 shows a top view of two such pushcarts, inserted inside eachother;

FIG. 3 shows a pushcart with a support section arranged in a stationarymanner; and,

FIG. 4 shows a top view of the pushcart shown in FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The pushcart shown in FIG. 1 has been designed in a known manner in sucha way that it can be inserted in a space-saving manner into an identicalpushcart 1. Its drive chassis 5 equipped with four casters 6, 7 istherefore constructed in the form of a taper, and its storage device 10intended for holding goods, for example a loading platform, is attachedto the drive chassis in a liftable manner. At the rear end 2 of thepushcart 1, a pushing device 11 that points backward is located. Belowthe storage device 10 and between the longitudinal bars 8 of the drivechassis 5 is located a support section 12 that is positioned at thefront end 9 of the drive chassis 5 in a manner swivable about ahorizontal axis 13. The support section 12 is intended for supporting arunning wheel 14 whose axis 15 extends transversely to the longitudinaldirection of the pushcart 1. The running wheel 14 is located, preferablyarranged in a center position, between the front and back casters 6, 7.The support section 12 is provided with an electromotor drive unit 16supplied by a power source 20 and intended for driving the running wheel14. The running wheel 14 can be driven, for example, via two gear wheelsor a friction wheel. But the preferred embodiment is a drive unit 16 inwhich the drive motor and the at least one running wheel 14 are combinedinto a single assembly. In the front part 4 of the pushcart 1, a powersource 20 is arranged below the storage device 10. The power source 20,usually formed by rechargeable batteries, is attached longitudinally tothe drive chassis 5 on at least one of the two sides of the supportsection 12.

FIG. 2 shows a top view of two pushcarts 1, 1′ according to FIG. 1inserted inside each other in a space-saving manner. The pushcart 1′shown in the left back has been inserted in a space-saving manner intothe pushcart 1 in front of it which is shown on the right. Since thepushcarts 1, 1′ can be only partially inserted inside each other, spaces18, 19 which are only claimed by one of the pushcarts 1 or 1′ remain. Inexpert language, these spaces 18, 19 are also called “stacking deadspaces”. In the drawing, the spaces 18, 19 are identified by the twodouble arrows. Space 18 is located in the frontal area 4 of the pushcart1, while the rear space 19 extends below the pushing device 11. Thedrawing clearly shows that the power source 20 arranged on both sides ofthe support section 12 is located in the space 18. Space 18 is notclaimed by the inserted pushcart 1′. In this way, space remains for thepractical accommodation of the power source 20 on pushcart 1. It is alsoadvantageous that the drive unit 16 is located advantageously in space18 guaranteeing the tightest possible insertion together of pushcarts 1,1′. In addition, it is also mentioned that a device 17 intended forlifting the support section 12 could be provided on each pushcart 1, 1′(see FIG. 1), for example as described in EP 0 352 647 B1.

FIG. 3. and FIG. 4 show a pushcart 1 whose drive chassis 5 and supportssection 12 can be designed in such a way as disclosed in U.S. Pat. No.4,826,186. The support section 12 is arranged in a stationary manner onthe drive chassis. Instead of only a single running wheel 14, tworunning wheels 14 are provided in an equivalent manner. Located onsupport section 12 and within the space 18, a drive unit 16 has againbeen provided, said drive unit being intended in the manner previouslydescribed for driving at least one of the two running wheels 14. Thedrive unit 16 is located in space 18, while the power source 20 in thisexemplary embodiment is located in space 19 that extends in the rearpart 3 of the pushcart 1 below the pushing device 11 and is locatedhigher than the storage device 10. In this exemplary embodiment thepower source 20 and the drive unit 16 also are located in at least oneof the spaces, 18, 19 not claimed by a pushcart 1, 1′ that is insertedduring the insertion process. In general, the power source 20 also couldbe located in both spaces 18, 19.

What is claimed is:
 1. A motor-assisted hand-movable cart that can havean identical cart inserted into it in a space-saving manner, whereby thecart comprises: a drive chassis having two front casters and two backcasters; a pushing device; a storage device for goods; a support sectionbelow the storage device, on which support section is disposed at leastone running wheel that is located between the two front and the two backcasters, and an electromotor drive unit, this drive unit for driving theat least one running wheel; and a power source for supplying theelectromotor drive unit located in a second space; wherein the secondspace is located below the storage device and in a front part of thepushcart.
 2. The motor-assisted hand-movable cart as claimed in claim 1,wherein the drive unit is designed as a single assembly comprising adrive motor and the at least one running wheel.
 3. The motor-assistedhand-movable cart as claimed in claim 1, wherein the drive unit islocated in a space not required by a further pushcart to be insertedinto the pushcart during the insertion process.
 4. The motor-assistedhand-movable cart as claimed in claim 1, wherein the power source islocated adjacent the support section on the drive chassis.
 5. Themotor-assisted hand-movable cart as claimed in claim 1, wherein thepower source is located on both sides of the support section on thedrive chassis.
 6. A motor-assisted hand-movable cart that can have anidentical cart inserted into it in a space-saving manner, whereby thecart comprises: a drive chassis having two front casters and two backcasters; a pushing device; a storage device for goods; a support sectionbelow the storage device, on which support section is disposed at leastone running wheel that is located between the two front and the two backcasters, and an electromotor drive unit, this drive unit for driving theat least one running wheel; and a power source for supplying theelectromotor drive unit located in a second space; wherein the secondspace is in a rear part of the pushcart, located higher than the storagedevice and below the pushing device.
 7. A motor-assisted hand-movablecart, comprising: a frame having two front casters and two back casters;a pushing device connected to the frame; a storage device for storinggoods, the storage device being connected to the frame; a supportsection connected to the frame below the storage device, on whichsupport section is disposed at least one running wheel that is locatedbetween the two front and the two back casters; an electromotor driveunit for driving the at least one running wheel; a power source forsupplying power to the electromotor drive unit; the cart including afirst space for receiving a portion of an identical cart when the cartand the identical cart are stacked together in a telescoping manner, andthe cart including a second space that is distinct from the first spaceand which is not occupied by any portion of the identical cart when thecart and the identical cart are stacked together in the telescopingmanner; and the power source is located in the second space; wherein thestorage device is connected to the frame in a liftable manner and thesecond space is located below the storage device an in a front part ofthe cart.
 8. A motor-assisted hand-movable cart comprising: a framehaving two front casters and two back casters; a pushing deviceconnected to the frame; a storage device for storing goods, the storagedevice being connected to the frame; a support section connected to theframe below the storage device, on which support section is disposed atleast one running wheel that is located between the two front and thetwo back casters; an electromotor drive unit for driving the at leastone running wheel; a power source for supplying power to theelectromotor drive unit; the cart including a first space for receivinga portion of an identical cart when the cart and the identical cart arestacked together in a telescoping manner, and the cart including asecond space that is distinct from the first space and which is notoccupied by any portion of the identical cart when the cart and theidentical cart are stacked together in the telescoping manner; and thepower source is located in the second space; wherein the storage deviceis connected to the frame in a liftable manner and the second space isin a rear part of the cart and located higher than the storage deviceand below the pushing device.